JPH0120743B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a binder for electrophotographic toner. In recent years, electrophotography has required high-speed recording, and high-speed fixing using a heat roll has become necessary. However, we have developed a binder resin that is suitable for high-speed fixing and also satisfies storage stability, offset resistance, and fixing properties. Not obtained.

The present invention is suitable for high-speed fixing using a heat roll,
Moreover, it is an object of the present invention to provide a toner binder that has excellent storage stability and offset resistance.

That is, the present invention provides (A) a polyolefin resin modified with an α,β-unsaturated monocarboxylic acid or dicarboxylic acid having a softening point of 90°C or higher, or an anhydride of the α,β-unsaturated dicarboxylic acid; B) One molecule contains at least one functional group that can react with the carboxyl group or acid anhydride group contained in the modified polyolefin resin (A) during heating, and a total of 2 or more, preferably 2 to 6 functional groups. do. The present invention relates to a binder for electrophotographic toner obtained by reacting with a polyfunctional crosslinkable compound.

Here, as the resin (A), for example, polyolefin resin is mixed with usually 0.5 to 15% by weight, preferably 1.0 to 10% by weight of α,β-unsaturated monocarboxylic acid or dicarboxylic acid, or Examples include polyolefin resins modified with anhydrides of α,β-unsaturated dicarboxylic acids, that is, unsaturated carboxylic acid (anhydride) modified polyolefin resins.
The softening point (ring and ball method) of the resin (A) is preferably 90°C or higher, preferably 95°C or higher. If the softening point is lower than 90°C, storage stability will be poor.

The polyolefin resin used in the present invention is a homopolymer or copolymer of ethylene, propylene, butylene, etc., and the comonomer is vinyl acetate,
Vinyl chloride, (meth)acrylic acid ester, etc. can be used. Further, halogenated polyolefin modified with chlorine or the like can also be used. Representative examples of α,β-unsaturated monocarboxylic acids, α,β-unsaturated dicarboxylic acids, and anhydrides of these dicarboxylic acids used for modification include acrylic acid, methacrylic acid, Examples include acid, monoalkyl maleate, monoalkyl fumarate, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride, and the like.

In addition, the polyfunctional crosslinkable compound (B) includes a lysidyl group that can react with a carboxyl group or an acid anhydride group,
A compound having a functional group such as a hydroxyl group or an amino group, such as a polyhydric epoxy compound such as bisphenol type epoxy resin, glycerin diglycidyl ether, paraoxybenzoic acid diglycidyl ester ether; ethylene glycol, propylene glycol, butylene glycol , polyhydric alcohols such as hexane glycol, glycerin, pentaerythritol, trimethylolethane, trimethylolpropane, etc.; polyhydric amines such as diaminodiphenylmethane, or an average of two or more hydroxyl groups in one molecule, Polyepoxy resins, polyesters, polyamides, polyurethanes, vinyl polymers, etc. containing one or more types of epoxy groups and amino groups can be used. The appropriate amount of these compounds (B) to be used is 0.05 to 10 equivalents, preferably 0.1 to 2.0 equivalents, based on the carboxyl group and acid anhydride group of the modified polyolefin resin (A).

The reaction between the modified polyolefin resin (A) and the polyfunctional crosslinkable compound (B) may be carried out in the presence or absence of other toner components such as carbon black. In addition, when manufacturing toner, we use modified polyolefin resin.
In addition to (A), the polyfunctional crosslinkable compound (B), and the coloring agent, polystyrene resins, polymethacrylic acid ester resins, coumaron resins, xylene resins, epoxy resins, polyester resins may be used as long as the purpose of the present invention is not impaired. , polyamide resin, rosin-modified maleic acid resin, and other known resins may be mixed.

By using the binder of the present invention,
It is possible to obtain a toner that is suitable for high-speed fixing with a heat roll and has good offset resistance and storage stability.

Next, the present invention will be explained in detail with reference to Examples.

Example 1 300 g of polypropylene (manufactured by Mitsui Toatsu Co., Ltd., JS-G), 1000 g of toluene,
5 g of maleic anhydride and 2 g of di-tertiary butyl peroxide were charged and reacted at 140° C. with stirring for 3 hours, and then the solvent was removed under reduced pressure to obtain a solid resin. The softening point of this resin was 135°C. Add neopentyl glycol to 100g of this resin.
1.0 g was added and reacted at 210°C for 1.5 hours. 8 g of carbon black is kneaded with 100 g of the obtained resin using a hot roll, cooled and pulverized to a diameter of 5 to 25 μm.
I got the toner.

When this toner was used to make copies using a high-speed copying machine, stable images were obtained even after 24 hours of continuous use. The offset resistance and storage stability were also good.

Example 2 The same as Example 1 except that 2.1 g of polyamide resin ("Laccamide N-153IM" manufactured by Dainippon Ink and Chemicals Co., Ltd.) was used instead of 1.0 g of neopentyl glycol as the crosslinking compound. I made toner using the exact same method as in step 1. When this toner was used to make copies using a high-speed copying machine, stable images were obtained even after 24 hours of continuous use.
The offset resistance and storage stability were also good.

Example 3 Chlorinated polypropylene (Superchlor
773H: 1000 g of a toluene solution with a chlorination rate of 32% and a non-volatile content of 45% (manufactured by Sanyo Kokusaku Pulp Co., Ltd.) and 5 g of maleic anhydride were placed in a 24-necked flask and reacted at 80°C for 12 hours. The resin was precipitated from the resulting solution with acetone and dried to obtain a solid resin. The softening point of this resin was 118°C.

1.0g of neopentyl glycol per 100g of this resin
was added and reacted at 200°C for 20 minutes. The same tests as in Example 1 were then conducted, and as a result, stable images were obtained, and offset resistance and storage stability were also good.

Example 4 300 g of ethylene-propylene copolymer (manufactured by Mitsubishi Yuka Co., Ltd., Noblen BC-3B), 4 g of methacrylic acid, 1000 g of toluene, and 2 g of t-butyl peroxybenzoate were placed in a four-necked flask (No. 2), and heated at 80°C. After reacting for 12 hours, the solvent was removed under reduced pressure to obtain a solid resin. The softening point of this resin is
It was 125℃.

Add 100g of this resin to epoxy resin (manufactured by Dainippon Ink Co., Ltd., Epicron 4050: epoxy equivalent 900-1000)
2g was added and reacted at 180°C for 30 minutes. The same tests as in Example 1 were then conducted, and as a result, stable images were obtained, and offset resistance and storage stability were also good.

<Offset resistance test> Paper, toner machine (thickness: 0.5 to 1.0 mm), and silicone rubber are stacked one after another on a hot plate, and a load of 100 g is applied thereto. After keeping the hot plate at 170°C for 5 minutes, check to see if the toner machine is fused to the silicone rubber, and the state of no fusion is considered good.

<Storage stability test> Put 100 c.c. of toner material into a 200 c.c. beaker, leave it in a constant temperature bath at a temperature of 40°C for 24 hours, then take it out and check whether there is any blocking development between the powders. Investigate,
Storage stability was considered to be good if there was no blocking.

Claims (1)

[Scope of Claims] 1 (A) A polyolefin resin modified with an α,β-unsaturated monocarboxylic acid or dicarboxylic acid, or an anhydride of the α,β-unsaturated dicarboxylic acid, having a softening point of 90°C or higher and (B) at least one functional group in each molecule that can react with the carboxyl group or acid anhydride group contained in the above-mentioned modified polyolefin resin (A) upon heating.
A binder for electrophotographic toner obtained by reacting a seed with a polyfunctional crosslinking compound containing two or more in total.